地震地质 ›› 2000, Vol. 22 ›› Issue (2): 129-138.

• 构造地质 • 上一篇    下一篇

阿尔金断裂带东段第四纪以来的水系位错与滑动速率

向宏发, 虢顺民, 张晚霞, 张秉良   

  1. 中国地震局地质研究所, 北京 100029
  • 收稿日期:1999-06-30 修回日期:1999-11-30 出版日期:2000-06-14 发布日期:2009-11-25
  • 基金资助:
    国家自然科学基金资助(49672149);中国地震局地质研究所论著2000B0018

RIVER OFFSET AND SLIP RATE OF THE EAST SEGMENT OF ALTUN TAGH FAULT ZONE SINCE QUATERNARY

Xiang Hongfa, Guo Shunmin, Zhang Wanxia, Zhang Bingliang   

  1. Institute of Geology, China Seismological Bureau, Beijing 100029
  • Received:1999-06-30 Revised:1999-11-30 Online:2000-06-14 Published:2009-11-25

摘要: 从阿克塞西红崖子向东经肃北至红柳峡口长约150km的范围内,通过沟、脊位错的分级与相关阶地年龄测试分析,将第四纪以来的水系位错量分为8级,并分别给出其形成年龄,得到各时段的断裂滑动速率介于4.7~6.7mm/a,平均值6.0mm/a,局部段落某个时段内最高滑动速率值7.7mm/a。位错量与滑动速率的空间分布有中间大、两头小的特点,这可能表明破裂从中间向两端发展的过程;在时间上,上新世以来的滑动速率比其它各个时段都大,这可能与青藏地块在距今5Ma以来的快速隆升及大规模挤出运动相关。资料表明,断裂破裂有从主体断裂某一段落扩展到邻近地带,最后又回到主体断裂其它段落的时空演化过程。

关键词: 水系位错与滑动速率, 时空分布, 阿尔金断裂

Abstract: Based on the gradation of stream and ridge offset and the dating of terrace sediments in a distance of 150km from Hongyaza in the west of Akesai eastward to Subei and Hongliuxiakou, the river offsets in Quaternary can be divided into 8 grades and their formation dates are acquired. The fault slip rates in different segments range 4.7~6.7mm/a. The average value is 6.0mm/a. As to the local section in a short period, the maximum slip rate can be 7.7mm/a. The distribution of offsets and slip rates shows that they are large at the middle and small at the ends, which may demonstrates that rupture initiates from the middle and develops towards the ends. The slip rate in Pliocene is larger than other epoches, which may be related to the quick lifting of Qinghai-Tibetan block since 5Ma B.P. and the large scale of escaping. Data show that fault rupture begins at the main fault, then extends to the vicinity and goes back the main fault.

Key words: Altun Tagh, River offset and slip rate, Temporal-spatial distribution